See the attached test case.
A h:panelGrid contains a header/footer f:facet.
In this facet we have a a4j:commandLink.
The link has a child element a4j:actionparam which assigns the value to a backing bean property.
Case 1: This link has the attribute "id" set.
Result: The AJAX request works as expected. The value is correctly assigned to the backing bean property.
Case 2: This link does not have the attribute "id" set.
Result: The first AJAX request works correctly. After that, every click results in an AJAX request, but the value is not assigned to the backing bean property.